Fluorescent tube changing device

ABSTRACT

A fluorescent tube changing device comprising a semi-cylindrical tube gripper pivotally mounted to a pole by means of a wrist block and frame assembly which serves as a compound pivot joint between the gripper and the pole and allows the freedom of movement and the necessary degree of control required to render the device useful as a quick and effective means for removing or installing a fluorescent tube in its fixture from a remote position.

1 Dec. 30, 1975 United States Patent [1 1 Hunt et al.

[54] FLUORESCENT TUBE CHANGING DEVICE 1/1958Panzlca................................. 3,342,519 9/1967 Hunt et al....

[76] Inventors: Joe B. Hunt; Nina E. Hunt; both of 3,799,599 3 1974Jordan..............1... ::::..1.:::... 294 20 3601 E. Orange Drive,Phoenix, Ariz. 85018 Primary Examiner-Robert S. Ward, Jr. AssistantExaminer.lohnny D. Cherry 22 Filed: Aug. 16, 1974 Attorney, Agent, orFirmWarren F. B. Lindsley 21 Appl. No.: 497,877

[57] ABSTRACT A fluorescent tube changing device comprising asemicylindrical tube gripper pivotally mounted to a pole by means of awrist block and frame assembly which serves as a compound pivot jointbetween the gripper and the pole and allows the freedom of movement and[56] References Cited UNITED STATES PATENTS the necessary degree ofcontrol required to render the device useful as a quick and effectivemeans for removing or installing a fluorescent tube in its fixture froma remote position.

Leibow 294/20 294/21 294/20 294/20 2 Claims, 4 Drawing Figures ma t. e"I "6 num df fen aw t BDS 5670 4445 9999 .1111 ll// 0 99 1 0022 20040 37 5374 00922 33 2222 US. Patent Dec. 30, 1975 FLUORESCENT TUBE CHANGINGDEVICE BACKGROUND OF THE INVENTION Probably the most common type ofartificial lighting employed today in factories, offices, stores andother large buildings is fluorescent lighting. Such installationscommonly utilize large numbers of lamps with a single installation oftenutilizing several hundred fluorescent tubes.

As the individual tubes inthese large installations fail or lose theirluminous intensity, they must be replaced. It has been found that themost efflcient maintenance practice in this connection is to replace allof the tubes in such an installation on a periodic basis as opposed towaiting for individual failures. The desirability of this practice restson the inefficiency of changing only a few lamps at a time when thefluorescent tubes gradually lose their luminous efficiency and totallight output and accordingly should be replaced periodically even thoughthey havenot failed.

While such large tube replacement operations are often handled bymaintenance personnel associated with the owners of the lightinginstallations, they are also quite frequently handled by smallenterprisers who contract to perform these services for others.

In a typical installation the fluorescent lighting fixtures are severalfeet above the floor and are inaccessible except by means of a ladder orscaffold. Very often, the location of furniture or equipment directlybelow the flxture makes it inconvenient or even impossible to useladders without moving the heavy furniture.

For these reasons and also because of the large numbers of lampsinvolved in a given installation, there is a need for a device whichwill permit an operator standing on the floor to remove and replace thetubes conveniently and quickly without the use of a ladder.

DESCRIPTION OF THE PRIOR ART Although US. Pat. Nos. 2,385,820;2,504,152; 2,543,607; 2,589,642; 2,658,786; 2,669,478; 2,819,922;3,lOl,2l2; 3,101,966; 9 3,129,970,

3,143,371 and 3,342,5l9 relate to lamp changing devices, none of themsatisfy all of the requirements of the trade, and employ in someinstances relatively complex mechanical assemblies. In many instances,no provision is made for rotating the lamps which are held by atwist-lock mechanism in the lamp sockets.

The mechanical structures of the prior art employ a number of fabricatedmetal parts which are expensive to manufacture and their designs havenot been optimized for the best utilization of plastic molding andextrusion processes or for. the best use of plastic parts to insure thestrength and durability of the working device.

SUMMARY OF THE INVENTION In accordance with the invention claimed, animproved fluorescent tube changing device is provided 2 the typeutilizing twist-lock as well as spring-loaded sockets.

A further object of this invention is to provide an improved fluorescenttube changing device having a compound pivotal joint which permits atwist-lock fluorescent tube to be rotated about its axis for removal orreplacement which device may be operated from an oblique angle withrespect to the longitudinal axis of the tube as opposed to directlybelow the tube.

A still further object of this invention is to provide an improvedfluorescent tube changing device which is simple in structure and whichmay be manufactured inexpensively utilizing molded or extruded plasticparts.

A still further object of this invention is to provide an improvedfluorescent tube changing device which permits the easy removal orreplacement of large numbers of fluorescent tubes in a very short periodof time.

Further objectsv and advantages of this invention will become apparentas the following description proceeds and the features of novelty whichcharacterize this invention will be pointed out with particularity inthe claims annexed to and forming a part of this specification.

BRIEF DESCRIPTION OF THE DRAWING The present invention may be morereadily described by reference to the accompanying drawing, in which:

FIG. 1 is a perspective view of the disclosed fluorescent tube changingdevice shown in relationship to a fluorescent tube shown in dash linesduring a removal or replacement operation;

FIG. 2 is a cross-sectional view of a pivot joint forming a part of thedevice shown in FIG. 1 taken along the line 22;

, FIG. 3 is a cross-sectional view of the device shown in FIG. 1 takenalong the line 3-3; and

FIG. 4 is a front view of the device shown in taken along the line 4--4.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring more particularly tothe drawing by characters of reference, FIGS. 1-4 disclose an improvedfluorescent tube changing device 10 comprising a semicylindricalfluorescent tube gripper 11 to which is fixedly attached two hingejoints, 12A and 12B, a two part frame assembly 13, a wrist block 14 anda handle 15, the gripper being pivotally attached to the frame assembly13 by means of a cylindrical shaft 16 which passes through cylindricalopenings in hinge joints 12A and 12B and an aligned cylindrical hole inframe assembly 13. The frame assembly l3'is pivotally attached to wristblock 14 by means of a cap screw 17 and a knob 18, the wrist block 14being detachably connected by means of a threaded coupling assembly 19to handle 15.

The semi-cylindrical tube gripper 11 comprises an elongated partiallyclosed cylinder having narrow flanges 21 extending radially outwardlyfrom the longitudinal edges of the semi-cylindrical configuration ofgripper 11. The inner surface of gripper 11 is lined by FIG. 1

a cushioning and friction affording material 22.

' of tube 23 and causing the semi-cylindrical gripper 11 to spread apartslightly as the tube 23 is forced into the gripper. i

The resilient cushioning and friction affording material 22 protects thefluorescent tube 23 against mechanical shock and prevents it fromslipping radially or longitudinally within the gripper during the tubechanging operations. Materials suitable for this use include any numberof tacky resinous materials, leather, sponge rubber or the like.

Hinge joints 12A and 12B are molded or extruded plastic parts having acentral hollow cylinder bore 24 and two supporting feet 25 and 26. Theinside diameter of hollow cylinder 24 is slightly greater than theoutside diameter of shaft 16 so that shaft 16 fits snugly insidecylinder 24 but is free to rotate therein. Feet 25 and 26 areprojections running at least a part of the length of one side ofcylinder 24 which rise a short distance as two parallel planes and thenbreak abruptly outwardly and apart from each other proceeding inoppositedirections along an arc of a radius corresponding to the radius ofcurvature of the outer surface of gripper 11. The mounting surfaces 27and 28 thus conform to the outer surface of gripper 11 and may bereadily and securely bonded thereto by a suitable plastic bondingmaterial such as methyl ethyl keytone.

Running longitudinally along the edge of cylinder 24 opposite thelocation of feet 25 and 26 are two additional substantially parallellyarranged projections or flanges 29 and 30. One or both of the hingejoints 12A and 12B may be forced together to reduce the inner dimensionsof cylinder 24 by a threaded bolt 32 passing through a pair of holes 33running perpendicularly through projections 29 and 30. A wing nut 34,washer 35 and spring 36 may be employed to draw projections 29 and 30together.

The two part frame assembly 13 has the general form of a common clevis,particularly when viewed in crosssection, as shown in FIG. 3, whereincap screw 17 serves as the clevis pin running through the diametricallypositioned holes 37 and 38 in its parts 13A and 138. These parts arefastened together at clevis neck 39 by means of four rivets 41-44 or thesurfaces may be bonded together. Just above neck 39, the twocounterpositioned parts 13A and 13B of frame assembly 13.

right angles to the shoulders 46 and 47 running parallel and immediatelyadjacent each other through neck area 39 whereupon they break abruptlyoutwardly following the contours of circular bore 45 until they meet andterminate at point 48' on the circumference of bore 45. The innersurface of bore 45 is thus cylindrical in form. Surrounding holes 37 and38 in parts 13A and 13B and rising from the outer surfaces of theseparts are two raised circular projections or hubs 48 and 49. Projection49 has a cavity shaped to contain and confine the hexagonal head of capscrew 17 to prevent it from turning. Projection 48 also has a cavitywhich must provide clearance for the body of cap screw 17 but for thesake of economy in production this cavity may have the same form asprovided for in projection 49 so that parts 13A and 138 may be identicalparts.

As shown in FIG. 1, parts 13A and 13B are molded with rib or web backsto reduce the weight and material content while still providing therequired strength. Five vertical ribs 58-62, uniformly spaced across thebreadth of neck 39, continue upwardly around the structure forming bore45 adding rigidity to this portion of assembly 13. Of these five ribs,the center rib 60 differs from the other four. While the other fourvertical ribs 58, 59, 61 and 62 are simply low profile ribs, rib 60 isan elongated cam-shaped projection having a purpose hereinafterdescribed.

Wrist block 14 has a diamond-shaped head 63 and neck 64 which isterminated in threaded coupling assembly 19. A circular hole 65 centeredin the diamondshaped head 63 has a diameter slightly greater than thediameter of cap screw 17. Head 63 is tilted slightly relative to thevertical center line 67 of neck 64 so that one edge 66 of thediamond-shaped contour of head 63 is approximately perpendicular to thecenter line of neck 64. The wrist block 14 has a thickness dimension 68which is somewhat less than the separation distance 69 between the innersurfaces of frame assembly 13. Wrist block 14 including head 63 and neck64 is molded in rib and web form to provide strength of structuresimultaneously with light weight. The overall width dimension 71 of head63 is slightly less than the overall width dimension 72 of frameassembly 13.

The various parts of device 10 are assembled as follows.

The two parts 13A and 13B of frame assembly 13 are placed back-to-backas shown in FIGS. 1 and 3 with shaft 16 inserted in bore 45 of frame 13.With shaft 16 centered in bore 45 so that equal portions of shaft 16extend from bore 45 at both ends, rivets 41-44 or the bonding of thesurfaces occurs. Shaft 16 is now fixedly and non-rotatably confinedwithin bore 45 and forms a single unit with frame 13. Hinge joints 12Aand 12B are then slipped over the protruding ends of shaft 16. The feet27 and 28 of joints 12A and 12B are then bonded to the undersurface ofgripper 11 as shown in FIGS. 1, 3 and 4.

Gripper 11 is now pivotally mounted by means of hinge joints 12A and 12Band shaft 16 to frame assembly 13. Wrist block 14 is then insertedbetween the parallel faces of parts 13A and 13B of frame assembly 13with the wrist block hole 65 aligned with holes 37 and 38. Two circularfriction washers 74 and 75 are inserted one on each side of wrist block14 with their central holes aligned with holes 37, 38 and 65. Cap screw17 is then installed through holes 38, 65 and 37. Coil spring 76 is thenslipped over shoulder 48 of part 13A of frame assembly 13 with a cupwasher 77 slipped over spring 76 as shown. Knob 18 is threaded over theprotruding end of screw 17 which is tightened against cup washer 77thereby compressing spring 76 against frame assembly 13. Two parts 13Aand 13B of frame 13 thus are drawn together thereby increasing thepressure between the mating surfaces of frame 13, friction washers 74and 75 and wrist block 14. Wrist block 14 The completely assembleddevice is seen to have two pivotal axes which are mutuallyperpendicular, namely the rotation of gripper 1 1 about the axisof shaft16 and the rotation of handle 19 and wrist block 14 about the axis ofcap," screw 17 supported within frame 13. Resistance to rotation in bothcases. is adjustable. As alreadydescribed, knob may be tightened orloosened to adjust freedom 'of r'otatiori of wrist block 14 about screw17. The freedom, of rotation of gripper 11 relative to frame assembly 13may similarly be adjusted by tightening or loosening wing-nut 34,thereby adjust- -ing the friction between hinge joint 12A and shaft 16.If

desired, hinge joint 12B also may be equipped with a screw 32, spring36, washer 35 and" wing-nut 34 to provide additional frictionaladjustment at that end of shaft 16. i

In operation to remove a twist-lock fluorescent tube, wing-nut 34 ispreferably loosened to allow gripper 11 to rotate freely relative toframe assembly 13. In preparation for the removal of the lamp, thegripper is first allowed to fall into the starting position-78 shown indash lines in FIG. 3, wherein gripper '11 rests against projection orstop 60 of frame assembly 13. The device 10 is then raised by means ofhandle and the gripper 11 is forced against the lamp until it snaps overthe walls of lamp 23 containing it within the cushioning material 22.Gripper 11 at this time is still in the starting position 78. The topend of device 10 is then forced to move in direction 79, as shown inFIG. 3 by applying pressure to handle 15. As frame assembly 13 moves indirection 79, the restrained fluorescent tube 23 is r0- tated within itssocket until its terminals become disengaged within its sockets. Tube 23is then easily removed from its sockets and is lowered and removed fromthe gripper by the operator of the device.

To install a new tube, tube 23 is first snapped into gripper 11 by theoperator, the gripper allowed to rest this time in position 81, shown indash lines in FIG. 3. Device 10 and lamp 23 are then raised to thefixture and the pins of lamp 23 are slipped into the lamp sockets.Gripper 11 is still in position 81. Frame assembly 13 is then forced tomove in direction 82, thereby rotating lamp 23 within its sockets tosecure its pins therein. Device 10 is then drawn away to disengagegripper 11 from tube 23 and the operation is completed.

To change a single-pin type fluorscent tube, gripper 11 is locked in theupright position shown by the solid line illustration in FIG. 3. This isaccomplished either by tightening wing-nut 34 or by utilizing screw 83and slot 84 as shown in FIG. 4. Slot 84 is located on hinge joint 12A toreceive the body of screw 83 as shaft 16 is moved longitudinally withinhinge joints 12A and 12B. The subsequent tightening of screw 83 withinslot 84 secures shaft 16 within hinge joint 12A so that rotation ofgripper 11 relative to frame assembly 13 is prevented.

To remove the single pin tube, gripper 11 is then slipped over the tubeand the tube is forced by pressure applied to handle 15 to move alongits longitudinal axis in the direction of its spring loaded socket untilthe opposite tube terminal is released from its socket. The tube is thenremoved from the spring loaded socket and lowered within gripper l 1 bythe operator. A new tube is next snapped into gripper 11 and installedby inserting the first terminal into the spring loaded socket,compressing the spring loaded socket to insert the 0pposite terminal,etc.

6 The-pivptal action of the wrist block 14 within frame assembly 13 isan important convenience'factor incorporated into the design ofdevice10. ln many instances furniture or equipment immediately below thefluoresthe .one shown by the solid line representation of FIG.

4 wherein handle l 5 is perpendicular to gripper 11, the other shown bythe dash line image wherein handle 15 is oblique to the longitudinalaxis of gripper 11 with edge. 66 of wrist block 44 bearing against innersurface 87 of frame assembly 13 to prevent further rotation. If suchlimits to rotation were not provided device 10 would be unwieldyand'awkward to operate.

A lightweight but'sturdy. device comprised almost entirely of moldedplastic parts requiring almost no machining operations is thus provided.The design of the individual parts has been optimized to preventover-stressing of individual parts without adding excessive weight tothe device which would unnecessarily tire the operator.

Installation and removal of lamps is accomplished very quickly by anoperator standing on the floor either directly below or from a positionbeyond one end of the fluorescent fixture. No time consuming cranking orlever moving operations are required, disengagement of the lamp beingaccomplished by nothing more than a quick sideward displacement of thehead of the device applied by the operator through the handle. The totaltime saved in changing out large numbers of lamps by virtue of this andother operating features of the device is considerable.

Although but one embodiment of the present invention has beenillustrated and described, it will be apparent to those skilled in theart that various changes and modifications may be made therein withoutdeparting from the spirit of the invention or from the scope of theappended claims.

What is claimed is:

.1. A device for changing fluorescent tubes and the like comprising:

a generally semi-cylindrical head having interior surface means of thesame size as the exterior periphery of a fluorescent tube arranged to beengaged therewith in response to transverse movement of said head towardthe tube,

said interior surface means having a tacky resinous material thereoncapable of sticking to the exterior periphery of the tube when contactedtherewith so as to prevent sliding movement of said interior surfacemeans with respect to the exterior periphery of the tube but to permitready disengagement of said interior surface means from the exteriorperiphery of the tube in response to transverse movement of said headaway from the tube,

and elongated handle connected with said head for effecting transversemovement of said head into engagement with the exterior periphery of atube to be changed and a subsequent movement of said head with the tubeengaged therewith to release the latter from its fixture and foreffecting movement of a replacement tube engaged with said head into 7securement with the fixture and subsequent transverse movement out ofengagement with the secured tube in the fixture,

said elongated handle being connected with said head by means providingfor a limited pivotal movement between said elongated handle and saidhead about a first axis parallel with the axis of said head and spacedclosely to the periphery thereof to facilitate a partial rotationalmovement of said head about its axis when in engagement with afluorescent tube of the type which is engaged and released from itsfixture by a partial rotational movement of the tube with respect to itsfixture,

said limited pivotal means comprising a pair of spaced cylindricalmembers fixedly secured to the center peripheral portion of said head,

a shaft means rotatably mounted within said cylindrical member andhaving an arm extending radially outwardly therefrom,

said shaft means being fixedly attached to said handle for rotationtherewith,

said handle and said shaft means being movable arcuately a predetermineddistance about said pair of cylindrical members until said arm engagesthe outer periphery of said head at which time partial rotationalmovement of said head about its axis occurs when in engagement with thefluorescent tube to release it from its fixture,

said limited pivotal means further comprising a pair of parallellyarranged juxtapositioned spaced surfaces connected along a common end tosaid shaft means,

stop means fixed to said handle and said handle being pivotally mountedbetween said spaced surfaces,

said stop means engaging said limited pivotal means upon rotation ofsaid handle about the pivotal connection of said handle to said spacedsurface, and

means for applying frictional force to said handle to control the easeof rotation of said handle between said spaced surfaces.

2. The device set forth in claim 1 wherein:

said means for applying frictional pressure to said handle comprises aspring bearing means mounted on the pivotal connection of said handle tosaid spaced surfaces for applying frictional pressure to the sides ofsaid handle.

1. A device for changing fluorescent tubes and the like comprising: agenerally semi-cylindrical head having interior surface means of thesame size as the exterior periphery of a fluorescent tube arranged to beengaged therewith in response to transverse movement of said head towardthe tube, said interior surface means having a tacky resinous materialthereon capable of sticking to the exterior periphery of the tube whencontacted therewith so as to prevent sliding movement of said interiorsurface means with respect to the exterior periphery of the tube but topermit ready disengagement of said interior surface means from theexterior periphery of the tube in response to transverse movement ofsaid head away from the tube, and elongated handle connected with saidhead for effecting transverse movement of said head into engagement withthe exterior periphery of a tube to be changed and a subsequent movementof said head with the tube engaged therewith to release the latter fromits fixture and for effecting movement of a replacement tube engagedwith said head into securement with the fixture and subsequenttransverse movement out of engagement with the secured tube in thefixture, said elongated handle being connected with said head by meansproviding for a limited pivotal movement between said elongated handleand said head about a first axis parallel with the axis of said head andspaced closely to the periphery thereof to facilitate a partialrotational movement of said head about its axis when in engagement witha fluorescent tube of the type which is engaged and released from itsfixture by a partial rotational movement of the tube with respect to itsfixture, said limited pivotal means comprising a pair of spacedcylindrical members fixedly secured to the center peripheral portion ofsaid head, a shaft means rotatably mounted within said cylindricalmember and having an arm extending radially outwardly therefrom, saidshaft means being fixedly attached to said handle for rotationtherewith, said handle and said shaft means being movable arcuately apredetermined distance about said pair of cylindrical members until saidarm engages the outer periphery of said head at which time partialrotational movement of said head about its axis occurs when inengagement with the fluorescent tube to release it from its fixture,said limited pivotal means further comprising a pair of parallellyarranged juxtapositioned spaced surfaces connected along a common end tosaid shaft means, stop means fixed to said handle and said handle beingpivotally mounted between said spaced surfaces, said stop means engagingsaid limited pivotal means upon rotation of said handle about thepivotal connection of said handle to said spaced surface, and means forapplying frictional force to said handle to control the ease of rotationof said handle between said spaced surfaces.
 2. The device set forth inclaim 1 wherein: said means for applying frictional pressure to saidhandle comprises a spring bearing means mounted on the pivotalconnection of said handle to said spaced surfaces for applyingfrictional pressure to the sides of said handle.